PH_Rule_SIGMA_2048
Enabled
Detects a network connection initiated by the certutil.exe tool. Attackers can abuse the utility in order to download malware or additional payloads. . This rule is adapted from https://github.com/SigmaHQ/sigma/blob/master/rules/windows/network_connection/net_connection_win_certutil_initiated_connection.yml
7
Security
Command And Control
T1105
Ingress Tool Transfer
Adversaries may transfer tools or other files from an external system into a compromised environment. Files may be copied from an external adversary controlled system through the command and control channel to bring tools into the victim network or through alternate protocols with another tool such as FTP. Files can also be copied over on Mac and Linux with native tools like scp, rsync, and sftp.
https://attack.mitre.org/techniques/T1105Server
Windows Sysmon via FortiSIEM Agent
Correlation
No remediation guidance specified
If the following pattern or patterns match an ingested event within the given time window in seconds, trigger an incident.
300 seconds
If the following defined pattern/s occur within a 300 second time window.
Filter
This is the named definition of the event query, this is important if multiple subpatterns are defined to distinguish them.
This is the query logic that matches incoming events
eventType REGEXP "Win-Sysmon-3-Network-Connect.*" AND procName REGEXP "\\certutil\.exe$" AND initiated="true" AND destIpPort IN (135,443,445,80)
This defines how matching events are aggregated, only events with the same matching attribute values are grouped into one unique incident ID
destIpPort,hostName,initiated,procName
This is most typically a numerical constraint that defines when the rule should trigger an incident
COUNT(*) >= 1
This section defines which fields in matching raw events should be mapped to the incident attributes in the resulting incident.
The available raw event attributes to map are limited to the group by attributes and the aggregate event constraint fields for each subpattern
destIpPort = Filter.destIpPort,
hostName = Filter.hostName,
initiated = Filter.initiated,
procName = Filter.procName